Who's using Ext at server side?

Since ExtJS is built on top of Ext Core which is hugely tied to DOM, there's little sense in trying to use ExtJS server-side. However, there are a lot of low level stuff in ExtJS that could be used to make a very nice server-side API/Library. For example, the whole OO Object scheme and Ext.extend() and Ext.isArray() type functions. The data stores and records are also not so tied to the DOM that they would be a good addition to a server-side API.